Connecting Pressure-Dependent Dynamics to Dynamics under Confinement: The Cooperative Free Volume Model Applied to Poly(4-chlorostyrene) Bulk and Thin Films

2018 ◽  
Vol 51 (20) ◽  
pp. 7924-7941 ◽  
Author(s):  
Ronald P. White ◽  
Jane E. G. Lipson
Keyword(s):  
Thin Films ◽  
Free Volume ◽  
Volume Model ◽  
Free Volume Model

scholarly journals Effect of an Improved Yasutomi Pressure-Viscosity Relationship on the Elastohydrodynamic Line Contact Problem

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Vincenzo Petrone ◽  
Adolfo Senatore ◽  
Vincenzo D'Agostino
Keyword(s):  
High Pressure ◽  
Film Thickness ◽  
Free Volume ◽  
Experimental Studies ◽  
Line Contact ◽  
Volume Model ◽  
Free Volume Model ◽  
Pressure Area ◽  
New Formulation ◽  
Lubricant Viscosity

This paper presents the application of an improved Yasutomi correlation for lubricant viscosity at high pressure in a Newtonian elastohydrodynamic line contact simulation. According to recent experimental studies using high pressure viscometers, the Yasutomi pressure-viscosity relationship derived from the free-volume model closely represents the real lubricant piezoviscous behavior for the high pressure typically encountered in elastohydrodynamic applications. However, the original Yasutomi correlation suffers from the appearance of a zero in the function describing the pressure dependence of the relative free volume thermal expansivity. In order to overcome this drawback, a new formulation of the Yasutomi relation was recently developed by Bair et al. This new function removes these concerns and provides improved precision without the need for an equation of state. Numerical simulations have been performed using the improved Yasutomi model to predict the lubricant pressure-viscosity, the pressure distribution, and the film thickness behavior in a Newtonian EHL simulation of a squalane-lubricated line contact. This work also shows that this model yields a higher viscosity at the low-pressure area, which results in a larger central film thickness compared with the previous piezoviscous relations.

Free volume model for positronium decay in molecular materials

1969 ◽  
Vol 28 (11) ◽  
pp. 760-761 ◽  
Author(s):  
B.V. Thosar ◽  
V.G. Kulkarni ◽  
R.G. Lagu ◽  
Girish Chandra
Keyword(s):  
Free Volume ◽  
Molecular Materials ◽  
Volume Model ◽  
Free Volume Model ◽  
Positronium Decay

scholarly journals On the free-volume model of multi-shape memory effect in amorphous polymer

2019 ◽  
Vol 28 (12) ◽  
pp. 125012
Author(s):  
Xiaodong Wang ◽  
Yuheng Liu ◽  
Haibao Lu ◽  
Yong-Qing Fu
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Free Volume ◽  
Memory Effect ◽  
Amorphous Polymer ◽  
Volume Model ◽  
Free Volume Model
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